Possible to reassign keyboard's punctuation keys?

Question

I am not referring to reassigning function keys, or to converting PC keyboards to OS X. I am asking if it is possible to reassign any key to any ASCII character.
What I want to do is make my semi-colon key and my apostrophe key swap duties. Is this possible? If so, how so?
If so, how does one remove and reattach the plastic key itself on a MBP?
Thank you for your help.

Answer 1

http://www.macupdate.com/info.php/id/14495
Ukelele can create and edit almost any kind of keyboard layout that is in the appropriate
XML format. You can modify the keyboard layout to produce any Unicode character,
or even short strings of Unicode characters.
What Ukelele can’t do
Ukelele is not intended for remapping modifier keys. For example, it is not intended
for swapping the command and option keys. Mac OS X 10.4 introduced some flexibility in
rearranging the modifier keys. Otherwise, other software, such as DoubleCommand (http://
doublecommand.sourceforge.net/), can do this and more.
Ukelele cannot turn a modifier key into a non-modifier key or vice versa. A modifier
key is one of shift, option, control, command, caps lock and fn. Again, DoubleCommand can
do some of this, such as turning the Enter key into a command key.
The fn key is not a modifier in the same sense that the shift key is. The fn key really
acts as a way for a notebook keyboard (as in PowerBook, iBook or MacBook) to simulate a
full-sized keyboard with a separate row of function keys (F-keys, F1–F15 or F16, or even F19)
and a numeric keypad. This effectively limits the fn key to working with only a subset of the
keys on the keyboard.
There are some keys which perform hardware functions such as controlling sound volume
or display brightness. Ukelele cannot change these functions.
There are some limitations imposed by Apple:
Mapping the arrow keys to something else, or other keys to arrow keys, is problematic.
It will work in some applications, but not others.
Control key combinations often do not work as desired. Often, control key combinations
are simply ignored, and sometimes they do something unexpected. There are some ways
around some, if not all, of the limitations, but these are not for the faint of heart!
Input methods, such as Chinese, Japanese or Korean, will not work with modified keyboard
layouts.
Kj